I have databound appointments that when I drag on them to move them they throw this error:

{"Value cannot be null.\r\nParameter name: g"}  Has anyone seen this before or better yet does anyone know how to fix it??

 Stack:

   at System.Guid..ctor(String g)
   at Infragistics.Win.UltraWinSchedule.Appointment.get_RecurrenceId()
   at Infragistics.Win.UltraWinSchedule.Appointment.InitializeFrom(Appointment source, Boolean afterSerializationCopy, Boolean copySubObjects, Boolean copyBindingInformation)
   at Infragistics.Win.UltraWinSchedule.Appointment.Clone(Boolean copyRecurrenceInfo, Boolean copyBindingInformation)
   at Infragistics.Win.UltraWinSchedule.Appointment.Clone()
   at Infragistics.Win.UltraWinSchedule.ActivityDragInfo.AddDuplicatedItems()
   at Infragistics.Win.UltraWinSchedule.UltraMonthViewSingleBase.Infragistics.Win.ISelectionManager.OnDragStart(ISelectableItem item, Point mousePosition)
   at Infragistics.Win.SelectionStrategyBase.DragStart()
   at Infragistics.Win.SelectionStrategyExtended.OnMouseMove(ISelectableItem item, MouseMessageInfo& msginfo)
   at Infragistics.Win.SelectionStrategyExtended.OnMouseMessage(ISelectableItem item, MouseMessageInfo& msginfo)
   at Infragistics.Win.ControlUIElementBase.ProcessMouseMoveHelper(Object sender, MouseEventArgs e)
   at Infragistics.Win.ControlUIElementBase.ProcessMouseMove(Object sender, MouseEventArgs e)
   at Infragistics.Win.Utilities.ProcessEvent(Control control, ProcessEvent eventToProcess, EventArgs e)
   at Infragistics.Win.UltraControlBase.OnMouseMove(MouseEventArgs e)
   at System.Windows.Forms.Control.WmMouseMove(Message& m)
   at System.Windows.Forms.Control.WndProc(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.OnMessage(Message& m)
   at System.Windows.Forms.Control.ControlNativeWindow.WndProc(Message& m)
   at System.Windows.Forms.NativeWindow.DebuggableCallback(IntPtr hWnd, Int32 msg, IntPtr wparam, IntPtr lparam)
   at System.Windows.Forms.UnsafeNativeMethods.DispatchMessageW(MSG& msg)
   at System.Windows.Forms.Application.ComponentManager.System.Windows.Forms.UnsafeNativeMethods.IMsoComponentManager.FPushMessageLoop(Int32 dwComponentID, Int32 reason, Int32 pvLoopData)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoopInner(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.ThreadContext.RunMessageLoop(Int32 reason, ApplicationContext context)
   at System.Windows.Forms.Application.Run(ApplicationContext context)
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.OnRun()
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.DoApplicationModel()
   at Microsoft.VisualBasic.ApplicationServices.WindowsFormsApplicationBase.Run(String[ commandLine)
   at WRGIAppraisals.My.MyApplication.Main(String[ Args) in 17d14f5c-a337-4978-8281-53493378c1071.vb:line 81
   at System.AppDomain._nExecuteAssembly(Assembly assembly, String[ args)
   at System.AppDomain.ExecuteAssembly(String assemblyFile, Evidence assemblySecurity, String[ args)
   at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
   at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
   at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.ThreadHelper.ThreadStart()

Thanks,

 Dan